METEOROLOGICAL OBSERVATORY 



OF THE 



Hatch Experiment Station, 



MASSACHUSETTS AGRICULTURAL COLLEGE, 



Latitude, 42° 23' 48.5" N. Longitude, 72° 31' 10" VV. 



Height of instruments above ground, 51 ft. Above sea level, 200 ft. 



BULLETIN No. 57. 



SEPTEMBER, 1893. 



MONTHLY SUMMARY. 



Pressure. In inches. 

 Actual maximum reatllng, . 30.165, 12th, 8 a 

 Actual minimum reading, . . 29.36, 16th, 9 a. 



Mean reduced to sea level, 30.065 



Monthly range, 805 



*Air Tetnperature. In Degrees Fahr. 



Highest 78,5th; 81,10th 



Lowest 38; 30, 27th 



Mean 58.1 ; 55.8 



Monthly Range, 40. ; 51 



Highest mean dally, 69.5; 68.5 



Lowest mean daily, 45.9; 43. 



Mean maximum 66.4; 69.5 



Mean minimum 49.4; 42.2 



Mean daily range, 17. ; 27.4 



Greatest daily range, 31. ; 42.5 



Least daily range 4. ; 13. 



Humidity. 



Mean dew point, 49.1 



Mean force of vapor, 5075 



Mean relative humidity 72.8 



Wind. 

 Prevailing Directions. 



South West, 24 per cent. 



North, 13 " " 



South, South West 12 " " 



South 10 " " 



Other directions 41 " " 



Total movement, 3.508 m. 



Greatest daily movement, . . . 248 m., 15th. 



Least daily movement, 33 m.; 27th. 



Mean daily movement llfi.9 m. 



Mean hourly velocity 4.9 m. 



Maximum pressure per square foot, l.)ilbs.= 

 54m. per hour, 30th, at 11 A. 



*f'recipitaiion. In inches. 

 Total precipitation, i.ss; 2.82 



Weather. 



Mean cloudiness observed, . . 45.7 per cent. 



Number of clear days, 8 



Number of fair days, g 



Number of cloudy days, 14 



Total cloudiness recorded by the Sun Ther- 

 mometer, ... 211 hours or 53 per cent. 

 Number of days on which .01 inch or more 



rain fell 7 



Frost 3d, 27th, 29th. 



Bright Sunshine, 



Number of Hours recorded 185 



Bain. . . 1st, 7th, 15th, 16th, 19th, 22d, 23d, 

 25th, 29th. 



Thunder and Lightning, 7th. 



Mean Ozone, 35 per cent. 



HaloSt 



Solar, Ist, 2l8t, 26th. 



Lunar 27th. 



Oales, of 35 or more miles per hour, ,37, 2d, 

 N.W.; 49 7th, N.; 40, 8th, N.N.E.; 37 

 16th, S.W.; 39, 17th, S.W.; 54, 30th, N. 



•The first figures denote readings at top of tower, the second at base. 



